Those gaining A-C grades at GCSE rose by 1.5 per cent to 68.1 per cent, the highest percentage since their introduction in 1988.
More pupils also scored an A* grade for outstanding performance. This figure edged up to 3.4 per cent.
The number of entries per pupil appears to have dropped however, despite an increase in the number of candidates entering for GCSE. This trend was noted last year and gave rise to speculation that schools were trying to save money by entering pupils for fewer subjects.
At A-level, the proportion of entrants passing their exams reached 90. 6 per cent, up from 89.7 per cent.
Almost a fifth of A-level students achieved a grade A, up 1.5 per cent on last year. The total number of candidates taking the exams slipped by 200 to 10,525.
The results were welcomed by Ulster's Council for the Curriculum Examinations and Assessment. A spokesman said: "This is the highest rate of A-C grades at GCSE that we have seen so far."
Catherine Coxhead, chief executive of CCEA, credited parents, pupils and teachers for the improvement in results.